Method for restoring acid etched glass

ABSTRACT

A method for restoring acid etched glass includes grinding the glass and then applying an acid resistant polyester film over the glass. Grinding may be performed in steps going from course to fine grinding pads, and stopping with a 400 grit pad, leaving a somewhat cloudy appearing surface. The polyester film fills in small irregularities in the cloudy glass surface thus eliminating the need to polish the glass.

BACKGROUND OF THE INVENTION

The present invention relates to restoring glass and in particular torestoring acid etched glass.

Tagging has long been a problem both due to the damage to property andto the gang related tagging. Glass dipping solution, and glass etchingcreams, are available at local craft stores. The solutions and creamsare made of chemicals, for example, hydrofluoric acid or ammoniumbiflouride. When the solutions or creams are applied to glass, the glasssurface is eaten away leaving a course etched surface. While cityordinances have been proposed to limit the sale of the etching solutionsand cremes, such solutions and creams also have legitimate uses, makingcontrol difficult.

In addition to acid etching, taggers and other vandals are known to usesharp objects, for example rocks, scribes, and the like, to etchwindows.

Unfortunately, even mildly etched glass is very expensive to replace orrepair using known methods. Large windows are more popular to etch, andalso more expensive to replace. Etched glass may be polished to removeetching, but such polishing is expensive, and the etching may berepeated as soon as the glass has been restored.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the above and other needs by providing amethod for restoring acid etched glass which includes grinding the glassand then applying an acid resistant polyester film over the glass.Grinding may be performed in steps going from course to fine grindingpads, and stopping with a 400 grit pad, leaving a somewhat cloudyappearing surface. The polyester film fills in small irregularities inthe cloudy glass surface thus eliminating the need to polish the glass.

In accordance with one aspect of the invention, there is provided amethod for restoring etched windows. The method comprises cleaning anetched region of the window, grinding with an electric hand heldgrinder, set to a low speed, until the etched region is a cloudy region,wetting an area overlapping the cloudy region to be covered with a filmwith a water solution, laying the film over the wetted area, andsmoothing the film against the window using a squeegee. The grindingincludes a final step of grinding with an approximately 400 grit pad tocreate the cloudy region, and may include earlier steps of grinding withmore course pads. The film is preferably an acid resistant polymerwindow film and preferably comprises three approximately two mil thicklaminated layers.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The above and other aspects, features and advantages of the presentinvention will be more apparent from the following more particulardescription thereof, presented in conjunction with the followingdrawings wherein:

FIG. 1A is a window with acid etching.

FIG. 1B is the window with a cloudy region resulting from grinding.

FIG. 1C shows the window with a polymer window film over the groundsurface.

FIG. 2 is a method for restoring an acid etched window according to thepresent invention.

Corresponding reference characters indicate corresponding componentsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best mode presently contemplated forcarrying out the invention. This description is not to be taken in alimiting sense, but is made merely for the purpose of describing one ormore preferred embodiments of the invention. The scope of the inventionshould be determined with reference to the claims.

A window 10 with acid etching 12 is shown in FIG. 1. The acid etching 12is commonly the result of taggers and is created by applying a solutionor cream glass etching chemical, for example, hydrofluoric acid orammonium biflouride. Although the window 10 may be polished to removethe etching, such polishing is time consuming, expensive, and the acidetching may be repeated. Further, each time a window is polished,material is removed, and therefore, a window may only be polished alimited number of times. Windows with scratches or etching created byrocks, sand paper, scribes, and the like, face the same issues.

The window 10 is shown in FIG. 1B after grinding the region containingthe acid etching 12 resulting in a cloudy region 14. The window 10 maybe ground using a 400 grit pad to produce the cloudy region 14, or maybe ground with a series of pads starting with a course pad, andfinishing with a 400 grit pad, for example with a 240 grit pad, a 320grit pad, and finishing with the 400 grit pad. The use of such coursepads is advantageous when the acid etching 12 is deep, and use of the400 grit pad alone would require an unnecessarily long grinding toremove the deep etching.

FIG. 1C shows the window 10 with a window film 16 over the cloudy region14. The window film 16 has a filling quality which dispels the cloudyappearance of the cloudy region 14 and provides a clear windowappearance. Additionally, the window of window film 16 is resistant tothe chemicals used for acid etching the window 10. Although, the windowfilm 16 may be cut or scratched it may be simply replaced withoutrequiring grinding the window again. Further, because the window film isnot susceptible to acid etching, taggers are less interested invandalizing windows covered with the window film 16.

An example of a suitable window film 16 is an approximately six milsthick polyester film, for example, three approximately two mils thicklaminated layers with a delayed tack adhesive backing. The layered filmis preferred because the layers tend to resist cutting better than asingle layer film. The Such window film is available from Madico inWoburn, Mass. and sold under the name LCL-600.

FIG. 2 is a method for restoring an acid etched window according to thepresent invention. The method includes cleaning the glass surface whennecessary, for example, when etching material is present on the glass,at step 20 and grinding the glass surface with an appropriate gritgrinding pad at step 22. Cleaning is generally necessary when residue ofthe etching solution or creme remains on the window. Grinding ispreferably performed using an electric hand held grinder and morepreferably a variable speed electric hand held grinder used at lowspeed, or a low speed electric hand held grinder. The grinding pad ispreferably selected from a range of pads including a 240 grit pad, a 320grit pad, and a 400 grit pad. The grit of the pad is selected based onthe depth of the etching, with a courser pad selected for deeperetching. Selecting too fine a pad, will not cause failure, but willrequire more time and effort to remove the etching. When the etching isdeep, and a course pad is used to remove the etching, the coursegrinding is followed in steps by grinding with finer grit pads. Forexample, deep etching may be removed with the 240 grit pads, the roughsurface created by grinding with the 240 grit pads may be smoothed bygrinding with the 320 grit pads, and a somewhat rough surface left bygrinding with the 320 grit pads may be ground with the 400 grit pads tocreate the cloudy surface 14.

Following the grinding, the glass may be inspected at step 24 todetermine if the etching has been removed. If the cloudy surface 14 hasnot been created, the grinding is continued at step 26 until the uniformcloudy surface 14 is created. A film layer is applied over the cloudysurface using the following steps: a water and soap solution is preparedat step 28, the area to be covered with the film is wetted with thewater and soap solution at step 30, the film is placed over the wettedarea at step 32, and the film is smoothed against the window at step 34.The smoothing is preferably performed using a squeegee.

While the invention herein disclosed has been described by means ofspecific embodiments and applications thereof, numerous modificationsand variations could be made thereto by those skilled in the art withoutdeparting from the scope of the invention set forth in the claims.

1. A method for restoring etched windows, the method comprising:cleaning an etched region of the window; grinding until the etchedregion becomes a cloudy region; and applying a window film over thecloudy region.
 2. The method of claim 1, wherein grinding comprisesgrinding with a grinding pad driven by an electric hand held grinder. 3.The method of claim 2, wherein grinding comprises grinding with avariable speed electric hand held grinder set to a low speed.
 4. Themethod of claim 3, wherein grinding until the etched region is a cloudyregion comprises: selecting a first grinding grit based on the depth ofthe etching; grinding with the first grinding grit until the etching isremoved; if a course grit was used, selecting a finer second grit toremove scratches from the first grit; continuing grinding until theetched region is a cloudy region.
 5. The method of claim 3, whereingrinding until the etched region is a cloudy region includes a finalgrinding step of grinding with a 400 grit pad to create the cloudyregion.
 6. The method of claim 1, wherein applying a window film overthe cloudy region comprises: preparing a water and soap solution;wetting an area overlapping the cloudy region to be covered with a filmwith the water and soap solution; laying the film over the wetted area;and smoothing the film against the window.
 7. The method of claim 1,wherein applying a window film over the cloudy region comprises applyingan acid resistant window film over the cloudy region.
 8. The method ofclaim 1, wherein applying a window film over the cloudy region comprisesapplying a polyester window film over the cloudy region.
 9. The methodof claim 1, wherein applying a window film over the cloudy regioncomprises applying an approximately 6 mil thick polyester window filmover the cloudy region.
 10. The method of claim 9, wherein applying anapproximately 6 mil thick polyester window film over the cloudy regioncomprises applying an approximately 6 mil thick polyester window filmcomprising at least two laminated layers over the cloudy region.
 11. Themethod of claim 10, wherein applying an approximately 6 mil thickpolyester window film over the cloudy region comprises applying anapproximately 6 mil thick polyester window film comprising threeapproximately two mil thick laminated layers over the cloudy region. 12.The method of claim 1, wherein applying a window film over the cloudyregion includes smoothing the film against the window using a squeegee.13. A method for restoring etched windows, the method comprising:cleaning an etched region of the window; grinding with an electric handheld grinder set to a low speed until the etched region is a cloudyregion including a final step of grinding with a 400 grit pad to createthe cloudy region; preparing a water and soap solution; wetting an areaoverlapping the cloudy region to be covered with an acid resistantpolymer window film with the water and soap solution; laying the filmover the wetted area; and smoothing the film against the window using asqueegee.
 14. A method for restoring etched windows, the methodcomprising: cleaning an etched region of the window; grinding with anelectric hand held grinder set to a low speed until the etched region isa cloudy region including a final step of grinding with a 400 grit padto create the cloudy region; wetting an area overlapping the cloudyregion to be covered with a window film with a water solution; layingthe film comprising three approximately two mil thick laminated layersover the wetted area; and smoothing the film against the window using asqueegee.